PMID- 37546644
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20230808
IS  - 2470-1343 (Electronic)
IS  - 2470-1343 (Linking)
VI  - 8
IP  - 30
DP  - 2023 Aug 1
TI  - Lignin-Based Polyurethanes from the Blocked Isocyanate Approach: Synthesis and 
      Characterization.
PG  - 27621-27633
LID - 10.1021/acsomega.3c03422 [doi]
AB  - Lignin, the world's second most abundant biopolymer, has been investigated as a 
      precursor of polyurethanes due to its high availability and large amount of 
      hydroxyls present in its structure. Lignin-based polyurethanes (LPUs) are usually 
      synthesized from the reaction between lignin, previously modified or not, and 
      diisocyanates. In the present work, LPUs were prepared, for the first time, using 
      the blocked isocyanate approach. For that, unmodified and hydroxypropylated Kraft 
      lignins were reacted with 4,4'-methylene diphenyl diisocyanate in the presence of 
      diisopropylamine (blocking agent). Castor oil was employed as a second polyol. 
      The chemical modification was confirmed by (31)P nuclear magnetic resonance 
      ((31)P NMR) analysis, and the structure of both lignins was elucidated by a 
      bidimensional NMR technique. The LPUs' prepolymerization kinetics was 
      investigated by temperature-modulated optical refractometry and Fourier-transform 
      infrared spectroscopy. The positive effect of hydroxypropylation on the 
      reactivity of the Kraft lignin was verified. The structure of LPU prepolymers was 
      accessed by bidimensional NMR. The formation of hindered urea-terminated LPU 
      prepolymers was confirmed. From the results, the feasibility of the blocked 
      isocyanate approach to obtain LPUs was proven. Lastly, single-lap shear tests 
      were performed and revealed the potential of LPU prepolymers as monocomponent 
      adhesives.
CI  - (c) 2023 The Authors. Published by American Chemical Society.
FAU - Antonino, Leonardo D
AU  - Antonino LD
AUID- ORCID: 0000-0002-6270-7074
AD  - Nanoscience and Advanced Materials Graduate Program (PPG-nano), Federal 
      University of ABC (UFABC), Santo Andre 09210-580, Brazil.
FAU - Sumerskii, Ivan
AU  - Sumerskii I
AD  - Department of Chemistry, Division of Chemistry of Renewable Resources, University 
      of Natural Resources and Life Sciences Vienna (BOKU), Konrad-Lorenz-Strasse 24, 
      3430 Tulln an der Donau, Austria.
FAU - Potthast, Antje
AU  - Potthast A
AUID- ORCID: 0000-0003-1981-2271
AD  - Department of Chemistry, Division of Chemistry of Renewable Resources, University 
      of Natural Resources and Life Sciences Vienna (BOKU), Konrad-Lorenz-Strasse 24, 
      3430 Tulln an der Donau, Austria.
FAU - Rosenau, Thomas
AU  - Rosenau T
AUID- ORCID: 0000-0002-6636-9260
AD  - Department of Chemistry, Division of Chemistry of Renewable Resources, University 
      of Natural Resources and Life Sciences Vienna (BOKU), Konrad-Lorenz-Strasse 24, 
      3430 Tulln an der Donau, Austria.
FAU - Felisberti, Maria Isabel
AU  - Felisberti MI
AUID- ORCID: 0000-0001-8311-9864
AD  - Institute of Chemistry, University of Campinas (UNICAMP), P.O. Box 6154, Campinas 
      13083-970, Brazil.
FAU - Dos Santos, Demetrio J
AU  - Dos Santos DJ
AD  - Nanoscience and Advanced Materials Graduate Program (PPG-nano), Federal 
      University of ABC (UFABC), Santo Andre 09210-580, Brazil.
AD  - Center of Engineering, Modeling and Applied Social Sciences, Federal University 
      of ABC (UFABC), Santo Andre 09210-580, Brazil.
LA  - eng
PT  - Journal Article
DEP - 20230718
PL  - United States
TA  - ACS Omega
JT  - ACS omega
JID - 101691658
PMC - PMC10398858
COIS- The authors declare no competing financial interest.
EDAT- 2023/08/07 06:41
MHDA- 2023/08/07 06:42
PMCR- 2023/07/18
CRDT- 2023/08/07 04:40
PHST- 2023/05/16 00:00 [received]
PHST- 2023/07/05 00:00 [accepted]
PHST- 2023/08/07 06:42 [medline]
PHST- 2023/08/07 06:41 [pubmed]
PHST- 2023/08/07 04:40 [entrez]
PHST- 2023/07/18 00:00 [pmc-release]
AID - 10.1021/acsomega.3c03422 [doi]
PST - epublish
SO  - ACS Omega. 2023 Jul 18;8(30):27621-27633. doi: 10.1021/acsomega.3c03422. 
      eCollection 2023 Aug 1.